Gas-blast circuit interrupter with primary and secondary blast valves

ABSTRACT

A gas-blast type of circuit breaker is provided having separable contacts with a primary blast valve closely adjacent the point of abutment of the separable contacts, and a secondary blast valve controlling the flow of gas through at least one of the separable contacts. In one embodiment of the invention, there is provided a pair of tubular separable contacts, through which the gas exhausts, and the region within both tubular separable contacts is controlled by downstream secondary blast valves mechanically connected together, and operated in response to opening motion of the separable contacts.

United States Patent Berkebile 1451 Aug. 22, 1972 '[22] Filed:

[54] GAS-BLAST CIRCUIT INTERRUPTER WITH PRIMARY AND SECONDARY BLASTVALVES [72] Inventor: Lee E. Berkebile, 11979 Frankstown Rd.,Pittsburgh, Pa. 15235 Sept. 16, 1968 21 Appl. No: 759,992

[52] US. Cl ..200/148 R, 200/148 BV [51] Int. Cl. ..H01h 33/82 [58]Field of Search ..200/148 BV, 148 B, 148

[56] References Cited UNITED STATES PATENTS 2,972,666 2/1961 Forwald..200/148 BV 3,040,149 6/1962 Easley et a1. ..200/148 BV 3,093,7176/1963 Forwald ..200/148 B 3,185,802 5/1965 Amalric ..200/148 B3,278,711 10/1966 Thuries et a1. ..200/148 B HIGH PRESSURE SF GAS I INTHIS REGION LOW PRESSURE SF GAS IN THIS REGION 3,286,066 1l/l966Floessel ..200/14813 Primary Examiner-Robert S. Macon Attorney-A. T.Stratton, C. L. McHale and W. R. Crout ABSTRACT A gas-blast type ofcircuit breaker is provided having separable contacts with a primaryblast valve closely adjacent the point of abutment of the separablecontacts, and a secondary blast valve controlling the flow of gasthrough at least one of the separable contacts.

In one embodiment of the invention, there is provided a pair of tubularseparable contacts, through which the gas exhausts, and the regionwithin both tubular separable contacts is controlled by downstreamsecondary blast valves mechanically connected together, and operated inresponse to opening motion of the separable contacts.

6 Claims, 5 Drawing Figures (A CLOSED CONTACT POSITION P'ATENTED M1822m2 SHEET 1 [IF 4 LOW PRESSURE SP GAS PATENTEDmszz m2 SHEEI 2 BF 4 FIG.2

K GAS-BLAST CIRCUIT INTERRUPTER WITH PRIMARY AND SECONDARY BLAST VALVESCROSS-REFERENCES TO RELATED APPLICATIONS The broad concept of a highgas-pressure region surrounding the region of separation and abutment ofthe separable contacts with the gas blast arranged to flow through theseparable contacts and controlled by a lo BACKGROUND OF THE INVENTIONPrior-art gas-blast circuit breakers generally involve a pair ofseperable contacts with an arrangement for providing a gas blast toeffect extinction of the arc drawn thereat. To create this gas blast,previous gasblast types of circuit breakers have employed blast valvesthat open just prior to contact part. Opening the blast valves creates apressure differential, and this differential pressure creates the gasblast. A limitation to this method is the time needed for the gas blastto travel from the blast valves to the are at the moving contacts. Thistime delay requires that the blast valves must be opened before themoving contacts are separated. In such a system, the maximum pressuredifierential (and therefore the greatest gas blast) does not occur atthe moving contacts at the time of. contact part. This inherent timedelay for maximum pressure differential limits the interruptingcapability of such prior-art compressed-gas circuit breakers in theiroperation.

A typical patent illustrating the use of a gas-blast valve disposedremotely from the separable contacts is US. Pat. No. 2,568,008 issuedSept. 18, 1951 to G. E. Janssen.

More recently, there has been proposed the use of separable contactsseparating in a high-pressure atmosphere with the gas blast exhaustingthrough at least one of the separable contacts. Such an arrangement isset forth in'U.S. Pat. No. 3,275,778 issued Sept. 27, 1966 to ShojiMorioka.

SUMMARY OF THE INVENTION In accordance with an embodiment of the presentinvention, there is provided a pair of separable contacts in ahigh-pressure gaseous atmosphere. A primary blast valve is disposedclosely adjacent the point of abutment of the separable contacts, sothat upon separation of the contacts there occurs an immediate radialinward flow of high-pressure gas into at least one of the separablecontacts. Controlling the flow of exhausting gas through said onecontact, or in particular arrangements through both separable contacts,is one or more secondary blast valves disposed downstream of the gasflow.

The mechanical arrangement is such that the downstream secondary blastvalves remain open for a predetermined time to insure an interruption ofthe are established between the separable contacts. At the point intime, where assurance is had that the arc has been extinguished, themechanical arrangement is such that the secondary blast valves close,thereby halting any further exhausting of the high-pressure gas throughthe separable contacts.

During a closing operation of the circuit breaker, the

primary blast valve, disposed immediately adjacent the point of abutmentof the separable contacts, insures a sealing condition at this point,and the mechanical arrangement during such a closing operation is suchas to open the one or more secondary blast valves, to thereby permit alowering of the pressure communicating with the region interiorly of theseparable contacts.

Accordingly, a general object of the present invention is to provide animproved high-speed compressedgas circuit interrupter having primary andsecondary blast valves, the primary blast valve being disposed closelyadjacent the point of separation of the separable contacts, and the oneor more secondary blast valves being located downstream of the gas flow.

Another object of the present invention is the provision of an improvedcompressed-gas circuit interrupter in which the separated open-circuitcondition of the contacts occurs in a high-pressure medium, therebyassuring a minimum separation distance because of the high-dielectricstrength of the high-pressure gas.

Still a further object of the present invention is the provision of animproved high-speed gas-blast circuit interrupter in which the timeoccurring between the opening of the blast valve and the separation ofthe separable contacts is at a minimum.

Another object of the present invention is the provision of an improvedcompressed-gas circuit interrupter in which the consumption of the gasflow during an opening operation is maintained at a minimum.

Another object of the present invention is the provision of an improvedsimplified-type of compressed-gas circuit interrupter of low cost andhighly efficient in operation.

Still a further object of the present invention is the provision of animproved compressed-gas circuit interrupter in which the arcing time ismaintained at a minimum to prevent voltage surges on the line, and aloss of synchronism of equipment connected to the line.

Further objects and advantages will readily become apparent upon readingthe following description taken in conjunction with the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a vertical sectional viewtaken through a circuit interrupter embodying my'invention, the contactstructure being illustrated in the closed-circuit position;

FIG. 2 is a sectional view taken substantially along the line 11-11 ofFIG. 1;

FIG. 3 is an enlarged view of the separable contact structure showingthe primary blast valve closed with the secondary blast valves opened,the contact structure being illustrated in the closed-circuit position;

FIG. 4 is a view similar to FIG. 3, but showing the separable contactstructure at an intermediate point during the opening operation, withthe primary blast valve opened and the secondary blast valves opened;and,

FIG. 5 illustrates the open-circuit position of the contact structurewith the primary blast valve opened and with the secondary blast valvesclosed.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawings, andmore particularly to FIG. 1 thereof, the reference numeral 1 designatesgenerally a compressed-gas circuit interrupter.

The lower end of the arc-extinguishing assemblage 2 of FIG. 1 iselectrically connected by a curved electrical conductor 4 to the otherterminal of the interrupter, not shown.

The compressed gas circuit interrupter 1 of the present invention isgenerally of the dual-pressure type in which high-pressure gas 5 isstored in a tank, not shown, and is disposed within container means 6immediately adjacent the separable contact structure 7 in the regiondesignated by the reference numeral 8 in FIGS. 1, 3-5. The region 9(FIG. 3) rearwardly of both contact structures 10, 11 is at relativelylow pressure. These regions are designated by the reference numeral 9,and are pneumatically interconnected by at least one interconnectingconduit designated by the reference numeral 12 in FIG. 1 of thedrawings.

Generally, the manner of operation of the circuit interrupter lillustrated in FIGS. 1-5 is the actuation of tripping valves. Theactuation of such tripping valves through a linkage causes the entranceof high-pressure gas 5 below piston structures not shown.

The upward movement of the piston structure, not shown, causes acorresponding upward opening motion of the mechanical linkage, orreciprocal operating means 19 (FIG. 2) which, in turn, causes upwardmovement of a generally ladder-type operating rod linkage 21, (FIG. 2)which interconnects the two secondary blast valves 23a, 23b associatedwith the arc-extin guishing unit 25 of the assemblage 2. In more detail,referring to FIGS. 3-5 of the drawings, it will be noted that there is apair of separable contacts 10, 11 having a primary blast valve structure27, and a pair of secondary blast-valve structures 23a, 23b. Thesecondary blastvalve structures 23a, 23b are mechanically interconnectedby the laddershaped operating linkage 21 (FIGS. 1 and 2), and aresimultaneously actuated.

Accordingly, to effect the opening operation of the compressed-gascircuit interrupter l of the present invention, the tripping valves isopened to cause the entrance of high-pressure gas 5 upwardly through theconduits and against the lower surfaces of the a piston structure, notshown. This causes upward opening movement of the ladder linkagearrangement 21, and, in addition, causes upward movement of an operatingrod 30 mechanically connected to the movable contact structure 10.Reference may be directed to the operating rod 30 of FIG. 3, which isconnected mechanically to the same operating rod 19 as shown in FIG. 2of the drawings.

Upward opening movement of the ladder-shaped linkage 21 causes openingof the movable contact away from the primary blast-valve seat 32 andseparation thereof from the stationary contact fingers 34, which makeengagement therewith in the closed-circuit position of the device, asillustrated in FIG. 3 of the drawings.

During the initial portion of the opening operation, both blast valves23a, 23b are opened, and the highpressure gas in the region 8 flowsradially inwardly and through both separable tubular contacts 10, 11exhausting therethrough into the regions 9 downstream of the separablecontacts 10, 11. This exhausting flow is controlled by the secondaryblast valves, 23a, 23b which are operated in unison.

With reference being particularly directed to FIGS. 3-5 of the drawings,it will be observed that the are 38, which is drawn between the contactfingers 34 and the extremity 10a of the moving tubular contact, isquickly transferred to the inner stationary tubular arcing contact 40being subjected to a flow of gas, as indicated by the arrows 41 in FIG.4 of the drawings. During this time, both primary and secondary blastvalves 27, 23a, 23b are opened. When the are 38 has been extinguished,it is desirable to halt the further consumption of high-pressure gas,and to effect this end, closure of the secondary blast valves 23a, 23bis desirable. This closing motion of the secondary blast valves isachieved by a flange portion 10b secured to the movable contact 10,which compresses a compression spring 43 and following the overcoming offriction at the seal 44, the secondary movable blast valve 23a is closedup against its seat 45, as illustrated in FIG. 5, thereby halting thefurther flow of compressed gas. The right-hand secondary blast valve23b, as illustrated in FIGS. 3-5 of the drawings is mechanicallyconnected to the laddershaped operating linkage 21, and therefore movessimultaneously with the left-hand secondary blast valve 23a. In otherwords, both the moving contact 10 and the flange portion 10b thereof,and also the operating rod 46, together with its actuator portion 46a,causes compression of the compression spring 43a and correspondingclosure of the right-hand secondary'blast valve 23b against its seat45a. The breaker is now in the open-circuit position with the primaryblast valve opened, and both secondary blast valves 23a, 23b closed, asshown in FIG. 5. The compression springs 43, 43a constitute a biasingmeans 13, tending to close the secondary blast-valves 23a, 2312, whichis steadily compressed, or stressed, during the opening operation tomechanically cause the closing of the secondary blast-valves.

During the closing operation, the high-pressure gas is exhausted fromthe lower surface of the piston structure, not shown, and thehigh-pressure gas which is constantly present above the pistonstructures causes the downward closing motion thereof. This iscommunicated through the ladder-shaped linkage 21, and also through theoperating rod 30 (FIG. 3) connected to the movable contact 10. As aresult, the moving contact 10 moves downwardly, as viewed in FIG. 1 ofthe drawings, and the operating rod 19, being connected to theladder-shaped linkage 21, also moves downwardly to thereby effectopening of the right-hand secondary blast valve 23b of. FIGS. 3-5. Thecircuit breaker is now in the closed-circuit position.

To enable the circuit breaker 1 to carry considerable current, there isprovided the two pairs of stationary contact fingers 34, 48 each ofwhich is supported by its contact holder 34a or 48a. The contact holdersare, as readily apparent in FIG. 3, bolted to the plate portions 50, 51constituting the ends of the low-pressureregions rearwardly of thestationary and movable contact structures 10, 11 reference being had toFIG. I in this connection.

From the foregoing description it will be apparent that there has beenprovided an improved high-speed compressed-gas circuit interrupter inwhich the contacts separate in a high-pressure atmosphere, orenvironment 8. The separation of the separable contacts not only causesopening of the primary blast valve 27 to result in a radial inward flowof the high-pressure fluid exhausting through the contacts, butcontinued opening motion effects a subsequent closure of the secondaryblast valves 23a, 23b and a cessation of the exhaust ing gas flowoccurring through both contacts. This results in the contacts beingseparated in a high-pressure region 8 while in the open circuitposition, thereby taking advantage of the high-dielectric-strength ofthe high-pressure gas. As well known by those skilled in the art, thisresults in a minimum separation distance in the open-circuit position ofthe interrupter.

Certain features of the operating mechanism are set forth and claimed inUS. Pat. application filed Sept. 25, 1968, Ser. No. 762,479, now US.Pat. No. 3,590,189, issued June 29, 1971 and assigned to the assignee ofthe instant application.

Certain other features relating to the general configuration of thecircuit interrupting structure with the generally U-shape are set forthand claimed in US. Pat. application filed Dec. 9, 1968, Ser. No.782,365, now US. Pat. No. 3,596,028, issued July 27, 1971, and likewiseassigned to the assignee of the instant application.

Although there has been illustrated and described specific structures,it is to be clearly understood that the same were merely for the purposeof illustration, and that changes and modifications may readily be madetherein by those skilled in the art without departing from the spiritand scope of the invention.

I claim:

1. A compressed-gas circuit interrupter comprising, in combination:

a. a pair of separable contacts at least one of which is tubular;

b. container means refining a high-pressure atmosphere about saidseparable contacts when they are in the closed-circuit position;

c. means defining a primary blast-valve located closely adjacent thepoint of separation of the separable contacts and preventing the inwardflow of said high-pressure atmosphere through the tubular separablecontact when in the closed-circuit position; means defining at least onedownstream secondary blast-valve independently movable from the movabletubular contact, and pneumatically connected to the region internally ofsaid one tubular contact to halt the continued flow of compressed gasthrough the tubular contact when the circuit-interrupter is in theopen-circuit position;

e. reciprocal operating means for effecting the opening and closingmovements of said one tubular venting contact;

f. biasing means provided to tend to close the secondary blast-valve;

a movable secondary blast-valve actuator responsive to the opening andclosing movements of said reciprocal operating means for mechanicallyeffecting the stressing of said biasin means during the openingoperation and also e ecting the subsequent closing of the secondaryblast-valve at a predetermined time during the opening operation toprevent thereby the further exhausting of compressed gas through thetubular venting contact at such time; and,

said movable secondary blast-valve actuator mechanically effecting theopening of the secondary blast-valve during the closing operation ofsaid operating means to thereby exhaust the region within the tubularventing contact in the closedcontact position.

2. The compressed-gas circuit interrupter of claim 1, in which bothseparable contacts are tubular and two secondary blast-valves areprovided.

3. The combination of claim ll, wherein the primary blast-valve isimmediately adjacent the point of abutment of the separable contacts.

4. The combination of claim 1, wherein two spaced stationary sets ofcontacts fingers bear on said one tubular separable contact forincreased current flow.

5. The combination of claim ll, wherein an inner arcing horn isassociated with the other separable contact.

6. The combination of claim 5, wherein the inner arcing horn is tubularand exhausts gas therethrough.

1. A compressed-gas circuit interrupter comprising, in combination: a. a pair of separable contacts at least one of which is tubular; b. container means refining a high-pressure atmosphere about said separable contacts when they are in the closed-circuit position; c. means defining a primary blast-valve located closely adjacent the point of separation of the separable contacts and preventing the inward flow of said high-pressure atmosphere through the tubular separable contact when in the closedcircuit position; d. means defining at least one downstream secondary blast-valve independently movable from the movable tubular contact, and pneumatically connected to the region internally of said one tubular contact to halt the continued flow of compressed gas through the tubular contact when the circuit-interrupter is in the open-circuit position; e. reciprocal operating means for effecting the opening and closing movements of said one tubular venting contact; f. biasing means provided to tend to close the secondary blastvalve; g. a movable secondary blast-valve actuator responsive to the opening and closing movements of said reciprocal operating means for mechanically effecting the stressing of said biasing means during the opening operation and also effecting the subsequent closing of the secondary blast-valve at a predetermined time during the opening operation to prevent thereby the further exhausting of compressed gas through the tubular venting contact at such time; and, h. said movable secondary blast-valve actuator mechanically effecting the opening of the secondary blast-valve during the closing operation of said operating means to thereby exhaust the region within the tubular venting contact in the closedcontact position.
 2. The compressed-gas circuit interrupter of claim 1, in which both separable contacts are tubular and two secondary blast-valves are provided.
 3. The combination of claim 1, wherein the primary blast-valve is immediately adjacent the point of abutment of the separable contacts.
 4. The combination of claim 1, wherein two spaced stationary sets of contacts fingers bear on said one tubular separable contact for increased current flow.
 5. The combination of claim 1, wherein an inner arcing horn is associated with the other separable contact.
 6. The combination of claim 5, wherein the inner arcing horn is tubular and exhausts gas therethrough. 